Firstly, the long wheelbase version is 207" (standard XJ is 202") and one of the longest on the market – a hair longer than even the new Mercedes S-Class. It’s also 3" wider and 0.5" lower ride than the XFR-S. Coupled with the 20" forged Farallon wheels, signature hood louvers, intercooler air ducts and front splitter, this Jag is a sleek ride.

Peeking inside, the opulent luxury was ushering us to climb in, but we jumped in the back for our initial ride. With 44" of rear legroom (6" longer than regular), it offers limousine space, complete with its own sunroof and armchairs.

The plethora of soft alcantara, the two-tone perforated and semi-aniline leather stamped with the “R” logo, the contrast stitching and carbon fiber veneers perfectly captured the combination of sport and luxury we’d been told to expect.

Encountering rough roads in the Northwest, the XJR’s Adaptive Dynamics suspension electronically varied the damping rates, allowing us to sail over the surface as if it were glass. This was definitely one car we wouldn’t mind being chauffeured in.

Fortunately, the XJR is equally enjoyable from the driver seat, with the steering surprisingly precise, given its 124" wheelbase.

Under the hood, the XJR’s supercharged 5.0-liter V8 is similar to the all-aluminum powerplants in the XJ Supersport and XJ Supercharged, but the R features cast iron sleeves and cross-bolted main bearing caps to cope with 550bhp – a 40hp and 80hp increase over its siblings, respectively.

This level of power combined with the XJ’s aluminum chassis gives the Jaguar a distinct advantage. To put it into perspective, the similarly powerful BMW M5 and Mercedes E63 AMG outweigh the XJR by 283 and 224 lb, respectively. And, while the outgoing Mercedes S65 AMG may boast more power, it out-porks the XJR by a whopping 937 lb!

With the same engine as the XFR-S, we noticed it was almost whisper quiet below 4000rpm. Above that speed, a valve opens on the intake manifold, directing more sound into the cabin to remind you what’s prowling under the hood.

Inevitably, the traction control comes in handy with 502 lb-ft of torque, which will easily light up the tires if turned off. At which point, you should be prepared to get sideways.

Zero-to-60mph takes 4.4sec but it’s at the mercy of available grip. However, the acceleration is exhilarating, especially in such a big car. And it won’t let up until the 174mph top speed governor, which is hiding the XJR’s actual top speed that’s closer to 200mph.

It’s not all power and wheelspin, though. In addition to its lightweight construction, Jaguar incorporated its Intelligent Start/Stop system so city slickers can save gas at the traffic lights. And if you need to make a quick getaway, the twin solenoid system will start the car in less time than it takes to fully press the throttle.

Our journey in the XJR would eventually lead us to Ridge Motorsports Park, which boasts a technical track with blind turns and elevation changes, a long straight, and Laguna Seca-like corkscrew.

Stereotypically, we imagined that putting the XJR through its paces here would be like powering down the Amazon River in a Cigarette boat. Yet the car overcame our doubts in surprising fashion. Even with its long wheelbase, the electronic suspension, big 15" brakes and wide tires provided great performance and plenty of grins. While understeer was expected, the right amount of trail braking meant it was never excessive. And, thanks to the four-piston brakes, 140mph down the front straight was easily scrubbed off before entering Turn 1.

Obviously, most XJR owners won’t see a racetrack but, while it wasn’t as agile as the shorter XFR-S, it was surprisingly easy to toss around, and our session enabled us to explore its performance in safe surroundings.

We were privileged to drive the XFR-S and XJR on the road and track. Both supercars in their own right; the shorter, sportier XFR-S took the track crown, while the longer, lighter XJR oozed luxury and comfort on the street. We’d gladly put either in our garage but, if we had to choose, we’d take the XJR, please.